Healing

Question 1

Haemostasis

Answer 1

Protective response to ruptured blood vessels
Prevent blood loss
Precursor for tissue repair
Rapid
Tightly controlled

Question 2

Haemostasis stages

Answer 2

1. Vascular spasm
2. Formation of the platelet plug
3. Coagulation

Question 3

Haemostasis - vascular spasm

Answer 3

Contraction of blood vessels
Slows blood loss
Neural reflexes And locally acting chemicals released from active platelets

Question 4

Haemostasis - formation of the platelet plug

Answer 4

1. Platelet adhesion
2. Platelet release reaction
3. Platelet aggregation

Question 5

Haemostasis - formation of the platelet plug: platelet adhesion

Answer 5

Stick to exposed collagen and connective tissue of damaged blood vessels

Question 6

Haemostasis - formation of the platelet plug: platelet release reaction

Answer 6

Release chemicals - ADP, thromboxane A2 and serotonin
Activate other platelets
Vasoconstriction

Question 7

Haemostasis - formation of the platelet plug: platelet aggregation

Answer 7

Passing platelets stick to the growing mass causing many platelets to accumulate at the site of blood loss

Question 8

Haemostasis - coagulation

Answer 8

Clot - blood cells trapped within a mesh of protein fibrin threads
Stimulated clotting factors - calcium ions, enzymes and chemicals
Clotting cascade

Question 9

Soft tissue healing - regeneration

Answer 9

Replaces destroyed tissue with the same kind of tissue

Question 10

Soft tissue healing - fibrosis

Answer 10

Replaces destroyed tissue with scar tissue (connective tissue)

Question 11

Soft tissue healing - inflammation

Answer 11

Release inflammatory chemicals
Local blood vessels leaky
White blood cells, fluid, clotting proteins and plasma proteins to the area
Clotting
Dries to form a scab

Question 12

Soft tissue healing - organisation restores the blood supply

Answer 12

Clot replaced by fragile capillaries - granulation tissue
Restores the vascular supply
Fibroblasts produce growth factors
Collagen fibres bridge the gap
Epithelial cells migrate over the granulation tissue

Question 13

Soft tissue healing - regeneration and fibrosis effect permanent repair

Answer 13

Fibrosed area contract pulling the wound together
Regenerates - epithelium thickens under scab
Scab detaches
Scar tissue

Question 14

Bone healing stages

Answer 14

1. Haematoma forms
2. Fibrocartilaginous callus forms
3. Bony callus forms
4. Bone remodelling

Question 15

Bone healing - Haematoma forms

Answer 15

Blood vessels in the periosteum are torn
The haemorrhaged blood clots
Bone cells die
Tissue becomes swollen, painful and inflamed

Question 16

Bone healing - fibrocartilaginous callus forms

Answer 16

Blood vessels grow into the clot
Fibroblasts - collagen fibres that span the break and connect the bone ends
Chondrocytes - secrete cartilaginous matrix that later calcifies forming a fibrocartilaginous callus
Soft callus

Question 17

Bone healing - bony callus forms

Answer 17

Osteoblasts begin forming spongy bone - lay down trabeculae within the fibrocartilaginous callus
Unit the two ends of the bone
Fibrocartilaginous callus replaced by immature bone converting into a bony callus

Question 18

Bone healing - bone remodelling

Answer 18

Excess material on diaphysis exterior and within medullary cavity is removes
Compact bone is laid down
Reconstruct the shaft walls